While the invention is subject to a wide range of applications, it is especially suited for precise measurement of materials being machined. In particular, the present invention is directed to a measurement probe which can be automatically attached or removed from a grinding head without any disturbance of the cutting tool.
Manufacturers of precision machine tools employ a number of different techniques to automate the process of machining parts to size. One method is to measure the position of the cutting tool with respect to the part being machined using a probe or pickup as a reference. This method is satisfactory when the position detected by the pickup is the same position or can be correlated to the position that the tool actually cuts. Examples of this technique are illustrated in U.S. Pat. Nos. 4,365,301 and 4,428,055.
A second method for automatically machining parts is to first roughly cut the part to size with a cutting tool. Then, the cutting tool, carried by a machine, is exchanged with a measurement probe and the machine measures the machined part. The measurement probe is removed and replaced with the cutting tool for the final sizing of the part. This method is described in U.S. Pat. Nos. 4,118,871; 4,145,816; and 4,203,225. Although this technique can work well, it is difficult to return the cutting tool to exactly the same position in the cutting tool holder.
A third method is to permanently mount a measurement probe directly to the tool holder. However, the probe is subject to vibrations which could affect its reliability. This general concept is illustrated in U.S. Pat. Nos. 3,559,257 and 3,605,909.
Still another method of measuring a workpiece is to provide an inspection system which is supported by the work table. This approach can reduce the flexibility of the size and shape of parts being machined. Examples of this arrangement are illustrated in U.S. Pat. Nos. 3,774,312; 4,070,762; and 4,296,474
It is a problem underlying the present invention to provide an automatic measurement system which attaches the probe member to the cutting tool holder at the time of measurement and automatically removes the probe once the measurement has been completed.
It is an advantage of the present invention to provide an automatic measurement system which obviates one or more of the limitations and disadvantages of the described prior arrangements.
It is a further advantage of the present invention to provide an automatic measurement system which precisely determines the shape of the workpiece being measured.
It is yet a further advantage of the present invention to provide an automatic measuring system which is relatively uncomplicated and easily retrofitted onto machines which presently incorporate the prior art techniques of measuring the workpiece.
It is a still further advantage of the present invention to provide an automatic measurement system which is relatively inexpensive to manufacture.
Accordingly, there has been provided an automatic measuring system and method of using the system. This system is incorporated into a cutting tool machine which includes a tool holder for mounting a cutting tool. A measurement probe is provided and automatically mounted and dismounted from the tool holder.